Wearable computing devices--including smartwatches, fitness and health tracking devices, and smartglasses--are projected to quadruple between now and 2018. What does their increased use mean for the performing arts? In their follow-up paper to "Through The Looking Glass: How Google Glass Will Change the Performing Arts," guest correspondents Thomas Rhodes and Samuel Allen explain wearable technology, provide an overview of current experiments with these devices among performing arts professionals, and discuss potential implications and challenges for the field.